This invention relates to a beverage dispensing system and a beverage distributing process which includes such a system. More particularly, the invention concerns such a process and system which incorporates a flexible container charged with the beverage and which serves as a storage and transport facility and also as a source from which the beverage is withdrawn on demand. Beverage dispensing systems are well known in which a flexible container is charged with a wine, soft drink, beer or cider and fitted with a tap so that as the beverage is drawn off by gravity or pump and on demand through the tap, the container collapses under atmospheric pressure to maintain the beverage remaining therein substantially without headspace. It is appreciated that containers for the aforementioned systems are formed with a flexible wall structure which is impervious to the contents, precludes the beverage from the external atmosphere and has negligible, if any, adverse effect upon the characteristics of the beverage. Generally the flexible wall structure is of plastics sheeting or metal foil or laminations thereof. A problem encountered with known dispensing systems as aforementioned is that the beverage when dispensed has little or no gas content (either dissolved therein or liberated in the form of a froth or head on the dispensed beverage) so that the beverage as dispensed is usually regarded as "flat". For many beverages such as beer, lager, stout, cider, wine and soft drinks there is a preference by the majority of consumers that the beverage when dispensed should contain a recognisable proportion of gas, conventionally carbon dioxide. The usual consumer preference is that the beverages as aforementioned should have more than one volume of carbon dioxide gas (as measured at 1 atmosphere and 0.degree. C.) dissolved therein for each volume of the beverage and which gas may be retained in the beverage by a pressure on the flexible container of 1 atmosphere. Whilst it is possible to charge the flexible container with beverage having carbon dioxide gas dissolved therein and to an extent much greater than, say, one volume of carbon dioxide gas per volume of beverage, it is found that during transport and storage of the container with the highly gasified beverage at ambient temperature, say 16.degree. C. or greater, the carbon dioxide gas is liberated and tends to inflate the flexible container so as to achieve an equilibrium condition in which the partial pressure of dissolved carbon dioxide gas is 1 atmosphere. This inflation will be maintained as the beverage is withdrawn from the container and the consequence is that the beverage as dispensed from a flexible container stored at atmospheric pressure will contain no greater volume of carbon dioxide than is achieved by equilibrium with a partial pressure of 1 atmosphere of carbon dioxide. It is well known physical law that the volume of carbon dioxide gas which can be dissolved in a given volume of beverage will increase as the partial pressure of carbon dioxide which is applied to the beverage increases and decreases as the temperature of the beverage increases; bearing in mind that the flexible container is to be subjected to atmospheric pressure, it can be determined from readily available tables that at 15.degree. C. approximately one volume only of carbon dioxide gas can be dissolved in one volume of beverage. Since it frequently occurs that a beverage may be dispensed from a flexible container in a known system as aforementioned and at a temperature in excess of 15.degree. C. It will be appreciated for the reasons previously discussed, that it is difficult to provide more than say one volume of carbon dioxide gas per volume of beverage in the beverage dispensed from said container. Even if the beverage within the container has dissolved therein one volume of carbon dioxide gas per volume of beverage, it will be apparent that this is far less than consumer preference and it is for this reason that known beverage dispensing systems of the kind previously discussed are primarily used for beverages which are acceptable to the consumer in a relatively un-gasified or flat condition. Flexible containers of the kind mentioned above are a convenient and economical means for the storage and transportation of beverage and there is a requirement for a beverage dispensing system and distributing process which includes a flexible container of the beverage that is collapsible under atmospheric pressure during dispensing of the beverage and from which the beverage can be dispensed having gas dissolved therein to an extent greater than that available with existing flexible container dispensing systems and without changing the characteristics of the beverage as it is progressively dispensed from the container--it is an object of the present invention to satisfy this requirement.